Context: Mentha x villosa Hudson (Lamiaceae) is an aromatic herb employed as a food spice. In folk medicine, it leaves are used as a tranquilizer and anti-hypertensive, even by pregnant women. Objective: There are no reports about its effects in gestation and exposed fetuses, the aim of this study. Materials and methods: At gestation day (GD) 01, 24 rats were divided in four groups: one control and three experimental groups (n = 6/group). The experimental groups received, by gavage, from GD06 to GD16, 10, 25 or 50 µg/kg/day of Mentha x villosa essential oil. The control group received the vehicle (Tween 80 and distilled water - 2%). The parameters of body weight gain, water and food intake were recorded. At GD20 the females were euthanized. Half of the fetuses from each litter were directed for the study of visceral malformations and the remaining fetuses for the study of skeletal malformations. Results: The statistical analyses revealed absence of alterations in body weight gain, water and food intake, litter weight, fetuses number and weight, reabsorptions and implantations. The treatment revealed absence of visceral and skeletal malformations. The visceral analysis revealed mild hemorrhagic points at brain, but more numerous at kidney, liver and blood vessels near heart, in some fetuses from some experimental litters. Conclusion: The essential oil was not able to promote impairment to the pregnant rats and to gestation. Even occurring lack of malformations, fetotoxicity was revealed by mild hemorrhagic points at liver, kidney, brain and blood vessels of some exposed fetuses.